A secondary battery cell, such as a lithium ion secondary battery cell, a nickel hydrogen secondary battery cell, a nickel-cadmium secondary battery cell and the like, has been spreading rapidly in recent years as a power source of a hybrid vehicle or an electric vehicle.
A secondary battery cell which is used as a power source for an automobile is made to be a storage battery module in which ordinarily, plural pieces of secondary battery cells are connected in series by a bus bar.
In a secondary battery cell, deterioration in a performance with regard to service life such as a reduction in capacity is liable to be brought about under a high temperature environment. Conversely, a reduction in an output of a battery is liable to be brought about under a low temperature environment.
Consequently, a secondary battery cell needs to be controlled at a pertinent temperature. Although it is inherently preferable to detect an inner temperature of a secondary battery cell, ordinarily, a surface temperature of a battery case of a secondary battery cell is detected by a temperature sensor in view of technology and in view of cost.
As such a structure, there is known a structure in which a temperature sensor is fastened to a bus bar connecting positive external terminals and negative external terminals of contiguous secondary cells, and a pair of lead terminals of the temperature sensor is soldered to a circuit pattern that is provided at a circuit board as described in Patent Literature 1.